The term “pyrotechnics” refers to materials capable of undergoing self-contained and self-sustained exothermic chemical reactions for the production of heat, light, gas, smoke, and/or sound. Pyrotechnic devices, using such pyrotechnic materials, are widely used in a number of aeronautical, aerospace, and even land-vehicle applications. Examples of pyrotechnic devices include explosive bolts, bolt cutters, separation fairings, actuators, engine igniters, etc.
In aeronautical and aerospace applications, for example, such pyrotechnic devices can be used for performing various functions such as separating one structure from another, releasing a structure from a stowed position to a deployed position, etc. Considering the specific example of a missile, a number of pyrotechnic devices may be assembled within the missile to perform a variety of operations. For example, one or more pyrotechnic devices may be used for engine ignition during the launch of the missile. Another set of pyrotechnic devices may be used at a later stage during the flight of the missile to achieve stage separation, etc. Similarly, in land-vehicle applications such as automobiles, pyrotechnic devices are now commonly used in the deployment of airbags.
Such pyrotechnic devices include several components, including an initiator, which in response to suitable electrical signals, initiates (or deploys) the devices. The pyrotechnic devices may also include an electronic assembly to control and coordinate the initiation of the initiator. One or more of these pyrotechnic devices are installed in an end system (e.g., airbag deployment systems, cruise missiles, etc.), where they are used through controlled deployment.
In some instances, each pyrotechnic device installed in the end system may perform the same function (e.g., bolt cutters in different sections of a launch vehicle). In other instances, as indicated above, different pyrotechnic devices may perform different functions (e.g., a group of pyrotechnic devices may be used as engine igniters and another group may be used as bolt cutters in a launch vehicle). In either case, a particular pyrotechnic device should be capable of being uniquely signaled such that a command (e.g., a firing command) can be transmitted to that particular pyrotechnic device. It is important to accurately identify these devices because a signal routed inadvertently to an unintended device may result in uncontrolled deployment in the end device.